1. Field of the Invention
This invention relates broadly to the field of construction and more particularly to the provision of new general purpose construction elements made from discarded pneumatic tire material. The construction elements provided by my prior U.S. Pat. No. 5,246,754 were primarily cylindrical in shape as posts, poles, or beams. This invention, on the other hand, recognizes that intermediate, generally rectangular shaped mats may be formed as a step in the production of such posts. The mats can be cut at one location and rolled in another. The formation of bales of such cut and flattened mats is convenient for transporting them to a post rolling site. Details of the mat cutting and post rolling operations are given in my prior U.S. Pat. No. 5,246,754. In addition, the bales of mats formed in accordance with this invention are separately useful as construction elements in their own right.
The instant invention also relates to the fields of environmental preservation and waste disposal, more specifically to recycling persistent non-biodegradable materials. Significant contributions are made to both fields by providing a new, useful, and inexpensive construction material which is easily made directly from a previously nearly indestructible item of scrap material causing worldwide disposal problems. The primary benefits to the environmental preservation and waste disposal industry are: (1) that the recycled product is made from the whole discarded item thus not creating more waste; (2) that the transformation to a useful product is done with very little energy expenditure; (3) that the entire process is virtually pollution free; and (4) that precious and dwindling forest resources may be preserved in that the product is contemplated to adequately replace wood in many applications.
The very toughness that makes old tire carcasses a difficult disposal problem lends strength and durability to the unique posts, poles, beams, stakes, girders, trestles, and supports made in accordance with the principles of my prior invention. This invention serves both to improve the efficiency of the manufacturing process of the old invention and to create another unique intermediate product which is useful in its own right. The new construction element proposed by the instant invention consists of bales of cut and flattened tire carcasses. It will become immediately evident that the unique physical properties of the construction elements produced in the manner herein disclosed will provide important benefits in many areas of the construction field.
The finished article of manufacture may take many forms as will be seen in the remainder of this specification. As such it will be appreciated that the potential uses are myriad. A comprehensive listing of all the possible fields to which this invention may be applied is limited only by the imagination and is therefore not attempted here. Some of the more obvious applications are mentioned herein in the interest of providing a full and complete disclosure of the unique properties of this hitherto unknown general purpose article of manufacture. Construction, environmental preservation, and waste disposal are seen as the fields most likely to gain immediate and substantial benefit from this invention. It is to be understood from the outset that the scope of this invention is not limited to these fields or to the specific examples of potential uses presented hereinafter.
2. Description of the Prior Art
From the outset it should be noted that the term rubber as used herein refers to the flexible material from which modern tires are formed in accordance with common usage. As such, the rubber bears little resemblance to the natural rubber made from the sap of the rubber tree. The vulcanized rubber pneumatic tire has proved to be both a blessing and a curse to modern society. We can't live without tires and we are just beginning to realize we can't live with millions of worn out tire carcasses clogging our landfills and littering our environment. Tires are particularly villainous at prematurely filling dump sites because their hollow toroidal shape is particularly volume consuming and they do not easily compress or nest within one another. About the only way anybody ever has gotten rid of a used tire has been to burn it. This solution has been so unsatisfactory that it is now illegal in most jurisdictions. Burning tires cause a horrible stench and pollute the air with toxic fumes and particles harmful to all life forms. Even expensive modern incineration devices, complete with scrubbers for the exhaust fumes, are inferior at destroying old tires. The steel belting materials clog the incinerator while the particulate carbon and sulfur compounds tend to foul the scrubbers. Additionally, many incineration devices consume electrical energy which serves primarily to transfer the pollution down the river to where the energy is being produced.
The difficulty in discarding worn out tires and the energy and raw materials required to manufacture them has inspired much effort to refurbish them for further use by retreading. However, there are several major problems with producing retread tires. The new tread which is to be bonded to the old tire must be produced somewhere. Extensive amounts of energy are used to produce the heat required to bond the new tread to the old tire and, even then, that crucial bonding is not always well accomplished. Both the bonding and the production of a new tread surface are, in many respects, just further examples of shipping the pollution down the river. All told, there is probably as much energy used and pollution produced in the manufacture of a retreaded tire as in the production of the original tire. Here, as in incineration, the steel belts and cords used in modern tires pose severe obstacles to the successful completion of the process. Not all tires can be effectively recycled by the retreading process. For example, if the sidewall or sealing bead is damaged there is no good means to reclaim that tire. The problem here is that a tire must not only have sufficient tread but must also meet stringent standards of flexibility, strength, air permeability, and appearance.
A second alternative of somehow reforming the old tire carcass into other useful articles has been pursued by others with generally limited success. It has been proposed that old tires could be shredded and used as a form of insulation material perhaps mixed with other insulation materials such as vermiculite. This proposal does indeed recognize the important property of extremely low thermal conductivity. The actual shredding process has proven extremely difficult, especially when steel belts are imbedded in the old tires. Even if the metal were successfully minced up with the rubber it would have to be separated later because it would seriously degrade the thermal insulation properties of the final product. Also, the actual volume of shredded material recovered in this manner would be relatively small with respect to the volume of the original tire carcasses. You would need a mountain of old tires to produce a truckload of shredded rubber insulation material, and that truckload might be enough to insulate one house. These relative quantities are, of course, not meant to be precise, but merely to point out the fact that there are problems of scale involved with shredding tire carcasses to produce a voluminous product such as household insulation.
Another use for shredded tire rubber has recently been proposed and given a certain amount of use with limited success. The shredded rubber is mixed with bituminous asphalt as a filler material in roadway construction. The long-term effectiveness of this use has yet to be determined. The above mentioned problems of scale are still present in forming the shredded rubber. Energy costs for the separation and shredding of the used tire rubber have, so far, proven to be economically prohibitive.
Following along with the idea of making some sort of useful product out of the old tire carcasses, there have been numerous proposals to create all kinds of decorative and ornamental articles from the tires. Examples of such uses are flower planters and landscape dividers. Two other applications of limited but useful merit will be familiar to all. Anyone from a farm or rural community will have seen a tire hung from a rope to form the familiar "tire swing". Anyone living on or near a body of water will have seen old tires attached to the sides of docks for cushioning the impacts of boats. This particular use highlights the important and useful impact absorption properties of the tire material.
Numerous examples of the prior art were considered in the examination of my prior patent. As will be seen, the simplicity and effectiveness of my invention is not rivaled in the prior art.
It has been recorded in the magazine "ABC-American Roofer and Building Improvement Contractor", February, 1978, that old truck tires have been flattened and used as a form of roofing. They are overlapped in an alternating tread-out tread-in pattern to form a watertight seal for this purpose. As best as can be determined, and in direct contrast with the instant invention, the sidewalls of the tire are removed and discarded prior to the flattening for use on a roof. By contrast, the instant invention proposes the forming of flattened mats from tire carcasses and the subsequent forming of bales of material by piling up and securing together the entire carcass mats, including the sidewalls.
Numerous United States Patents have been granted for various and sundry articles made from old tires. The largest group of these Patents are concerned with providing highway safety dividers or barriers thus effectively utilizing the inherent impact energy absorption characteristics of the rubber. Bruner et al, U.S. Pat. No. 4,186,913, shows an arrangement of side-by-side upright tire casings supported in a solid rubber block which is poured around the lower portions of the tires. Bruner also mentions the possible use of this arrangement as a breakwater. Ward, U.S. Pat. No. 4,030,706, shows a highway bumper guard made from two tire casings arranged concentrically within one another and with the inner casing being filled with particulate material such as sand. Ward recognizes that this arrangement will absorb impact energy by virtue of the friction between the concentric tires. As will be seen later, this type of internal friction can also be an important feature of my invention. Yoho, U.S. Pat. No. 4,066,244, shows an arrangement of upright tire casings connected together in transverse lines and rows for the purpose of absorbing impact energy. Schaaf et al, U.S. Pat. No. 4,312,600, discloses a traffic barricade, or marker, whose base is formed from a horizontal tire casing. Schaaf recognizes that the interior portion of the tire casing may be filled with a buoyant material thus forming a buoy marker. By contrast none of these inventions contemplates the cutting, flattening, stacking, and securing of tire carcasses so as to form the bales of the instant invention.
Other miscellaneous exploitations of used tire casings are shown by Doring, U.S. Pat. No. 4,142,821 and by Moore, U.S. Pat. No. 4,022,434. Doring shows ground stabilization devices for embankments, etc., made from variously interconnected loops of tire treads with the sidewalls removed. Moore shows a means of stacking and interconnecting upright tires to form a fence. The tire fence is supported by partially burying the lower course of tires. Moore recognizes yet another important property of the tire material, low electrical conductivity. Moore exploits this property by stringing electrified barbed wire directly from his fence without the need for expensive electrical insulator offset devices of any kind. As will be seen later, this is another property which enhances the overall desirability of my invention. By contrast, my invention proposes the cutting and flattening of entire tire carcasses followed by stacking them into bales or blocks.
The many and varied previous uses for old tire casings serve to illustrate and take advantage of the important property of chemical inertness. Tire casing material will not rot, decay, decompose, deteriorate, or easily disintegrate. Tire casings are impervious to attack from mold, fungus, or bacteria, or other micro-organisms. Insects, rodents, birds, bats, deer, barnacles, and other animals can not destroy tire casings. Corrosive agents, such as salt water and most acids, do not harm tire casings. Prolonged exposure to ultra-violet radiation does not degrade tire casing material. Tire material will withstand extreme climatic temperature ranges without substantial deterioration of its excellent strength and toughness characteristics.
In spite of the many and varied uses for old tire casings proposed by the prior art, it is well known that old tires are most often discarded in garbage dumps where they often collect stagnant water and serve as breeding grounds for mosquitoes and other pests.
My invention proposes a new product, made from those old tires, whose usefulness is so general and application so broad that old tires will no longer need to be discarded and, in fact, may become valuable commodities.
None of the above inventions and patents, taken either singly or in combination, is seen to anticipate or make obvious the instant invention as claimed.